CA License #1119373Licensed, Bonded & InsuredPowered by Future Generation ConstructionFuture Generation
San Jose ADU Builder
Sacramento-built ADUs for the San Jose backyard.
We're a Sacramento design-build crew that takes the bigger San Jose jobs, the Willow Glen bungalows and Almaden hillsides and Berryessa flats, and brings real craftsmanship at numbers worth the 130-mile drive.
Trusted by homeowners across Sacramento & surrounding areas.
ADUs in San Jose — fast facts
County
Santa Clara County
Region
Bay Area
ADU types we build
Detached, Attached, Garage Conversion, Custom
Contractor license
CSLB #1119373
Free estimate
(916) 677-9774
Last updated
San Jose lots are not Sacramento lots
A San Jose tenth-acre, a six-figure footprint
San Jose breaks every habit a Sacramento builder shows up with. A flat 6,000 sq ft Willow Glen lot feels generous here, the bungalow sits ten feet off the line, and the dirt is worth more per square foot than the house — so you're carving livable space out of land that already costs a fortune, which is why an ADU pencils at Bay Area prices. Our PM opens every free walk on what your lot can hold: real setbacks taped off the fence, not the assessor map, and whether side-yard access is a 34-inch gap, because then concrete and lumber get craned or carried. Cambrian and Berryessa give you room; Naglee Park and the Rose Garden often don't.
Free on-site walk before a dollar gets committed
Real setbacks taped off the fence line, not the parcel map
Tight-access lots flagged up front: crane vs. carry priced honestly
The San Jose catch we won't sugarcoat
Evergreen clay and Almaden hillside foundations
Here's the honest negative, and it's a big one. The east-side hills — Evergreen, Silver Creek, Mount Pleasant — and the west-side benches under Almaden and Santa Teresa carry expansive clay, old landslide deposits, and slopes steep enough to trigger the city's hillside rules, so an ADU there gets drilled piers or a stepped grade-beam foundation, adding $25K to $70K over a flat-lot build. Toward Alviso and the baylands the ground flips — low, soft, inside liquefaction mapping. Even the friendly Willow Glen, Cambrian, and Berryessa flats carry enough valley clay that we won't assume a standard slab, so we read your dirt on the first visit and pull a geotech report wherever slope or liquefaction is in play.
Hillside lots (Evergreen, Almaden, Silver Creek) priced for piers and grade beams up front
Geotech report pulled where slope, clay, or liquefaction is in play
Foundation cost engineered to your soil, never sprung mid-build
Permits, in plain English
The City of San José counter and its plan shortcut
Your San Jose ADU goes through the City of San José, not Santa Clara County, run by the Planning, Building and Code Enforcement department, PBCE. California killed discretionary review, so once a compliant set clears plan check the city has to issue — no neighborhood hearing torpedoes your unit. San José has also leaned into ADUs with a pre-approved standard plan lane that shaves real review time on a flat lot, and we'll flag whether it fits your lot. The honest part: PBCE runs big-city volume, so even with the 60-day state clock, corrections and utility sign-offs push permit timing to about 10 to 16 weeks. We fight that with a full in-house set that goes in clean.
Permit pulled through City of San José PBCE, a city project, not county
Pre-approved / standard ADU plan lane evaluated for your lot
Complete in-house set (site, structural, Title-24, MEP), corrections answered by the drafter
Real San Jose numbers
Willow Glen build costs and Silicon Valley rents
Forget the Sacramento numbers; Bay Area pricing is its own animal. In San Jose, a 612 sq ft one-bedroom detached ADU with mid-grade finishes runs roughly $360K to $445K all-in for 2025–2026 on a flat lot; a 976 sq ft two-bedroom lands closer to $510K to $640K. An Evergreen or Almaden hillside adds $30K to $60K in foundation alone, and the land value is what makes it pencil. Rent is the reason: a one-bed pulls about $2,450 to $3,100 a month, a two-bed $3,200 to $4,200, Silicon Valley demand keeping it occupied fast. Every prospect gets a fixed-price proposal after the free walk, financing if you want it, and a change order only comes from a finish upgrade — never a missed soil, access, or slope.
612 sq ft detached one-bed: roughly $360K–$445K all-in on a flat lot (2025–2026)
San Jose one-bed ADU rents around $2,450–$3,100/mo; two-bed $3,200–$4,200
Fixed-price contract with itemized scope, financing available if you want it
ADU Services
Pick the ADU that fits your San Jose lot
Detached, attached, garage conversion, or fully custom — we design, permit, and build every type of ADU under one roof in the Greater Sacramento Area. Tap a card for the details.
“Every ADU we build is designed to add long-term value and open new possibilities for your property. Let's build something great together.”
— Tim, ADU Specialist
Custom Designs
Built to fit your property & needs
Turnkey Process
We handle permits, plans & everything
Built to Last
Quality craftsmanship that stands the test
Financing Made Simple
$0 Down Options. Build Now, Pay Over Time.
You shouldn't have to drain your savings to build wealth. We partner with trusted ADU lenders to find financing that fits — many homeowners build with little to nothing out of pocket.
Home Equity (HELOC)
Tap your existing equity at competitive rates — the most popular way to fund an ADU.
Renovation Loans
Finance the build against your home's projected after-completion value.
ADU-Specific Financing
Specialized lenders who underwrite based on the rental income your ADU will produce.
Cash-Out Refinance
Roll the project into a new mortgage and keep one simple monthly payment.
Estimate Your Monthly Payment
See what financing your ADU could look like — and how rental income can help cover it.
$180,000Loan amount
Credit Score
Very good · 700–739
Estimated Monthly Payment
$1,320/mo
At 7.99% APR over 30 years (illustrative)
Often offset by $2,000–$3,500/mo in rental income
No prepayment penalties with most partners
Pre-qualification with no impact to your credit
Illustrative only — not a loan offer. Actual rates and terms are set by third-party lenders based on your qualifications.
Service areas
Where we build
Headquartered in the Greater Sacramento Area and serving homeowners from the Sierra foothills down through the Bay Area. Don't see your city? We probably still get there — just ask.
The most common things Sacramento homeowners ask before starting an ADU project.
The City of San José, in almost every case. San Jose is an incorporated city with its own Planning, Building and Code Enforcement department (PBCE), and your ADU's permit, plan check, and inspections all run through the city downtown. Santa Clara County's building department only has authority over unincorporated land — the foothill parcels and rural pockets outside the city limits, places like the unincorporated stretches up toward the east-side hills or out past the urban edge. If your house sits on a San Jose street with city sewer, you're a city project. We confirm which jurisdiction governs your exact lot on the first visit so a set never lands on the wrong counter.
Usually yes, but it's the first thing we check, because San Jose lots are small and the answer drives the whole design. State law lets you build a detached ADU up to 800 sq ft (and often larger) with reduced 4-foot side and rear setbacks, which is what makes tight urban lots work at all. The real constraint is rarely the rule — it's the physical yard: how much flat usable space sits behind the house, and whether the only side-yard access is wide enough to get a crew and concrete back there. A Cambrian or Berryessa lot often has room to spare; a Naglee Park or Rose Garden lot can be snug. We tape your real setbacks and measure the access gap on the first walk so the floor plan fits the dirt you actually have.
Because the Bay Area is its own cost world, top to bottom. Labor rates, material delivery, the price of working on small tight-access lots, hillside foundations, and city fees all run higher in San Jose than in the Sacramento region. A flat-lot 612 sq ft one-bed that might be in the low $200Ks inland runs roughly $360K to $445K all-in here. The flip side is the rent and the land value: San Jose one-beds rent for $2,450 to $3,100 a month and the underlying lot is worth a fortune, so the investment still pencils even at Bay Area build prices. We're upfront about the number on the first visit — no bait-and-switch off an inland price sheet.
A lot. Slope is the single biggest cost swing on San Jose's east-side and west-side hills. Evergreen, Silver Creek, the climbs toward Mount Pleasant, and the benches under Almaden and Santa Teresa carry expansive clay, old landslide deposits, and grades steep enough to trigger the city's hillside development rules. On a parcel like that an ADU needs an engineered foundation, drilled piers or a stepped grade-beam design, plus a geotech report before anyone pours, which can add $25K to $70K over a flat-lot build. It's not a reason to skip the project; it's a reason to price it honestly. We read the slope and the soil on the first visit and pull the geotech where it's warranted, so the foundation line in your proposal is real engineering.
On a friendly flat lot, budget about $360K to $445K all-in for a 612 sq ft one-bedroom detached ADU with mid-grade finishes, and roughly $510K to $640K for a 976 sq ft two-bedroom with upgraded finishes. The biggest cost drivers after size are the foundation, where a hillside or bayland lot can add $30K to $60K-plus over a standard slab, plus any electrical panel upgrade and how tight your side-yard access is. You get a fixed-price proposal after the free walk, so the final number is locked before you sign rather than guessed at.
It does, and on the right lot it's genuinely useful. The City of San José runs a pre-approved / standard ADU plan program, where the city has already vetted certain designs so plan check moves faster than a fully custom set. On a flat, straightforward lot that can trim real time off review. It isn't the right fit for every project — a tight, sloped, or character-sensitive lot, or a homeowner who wants a specific layout, is often better served by a custom in-house set. We'll look at your lot and tell you straight which lane saves you more time and money rather than defaulting to one.
California puts a 60-day clock on the City of San José to approve or return corrections on a complete ADU application, and discretionary review is gone, so there's no neighborhood hearing to derail you. That said, San José's PBCE counter handles big-city permit volume, and between corrections, utility and school-fee sign-offs, and any hillside or historic-overlay layer, realistic timing from signed contract to permit in hand runs about 10 to 16 weeks here — longer than a small Sacramento suburb. The main variable is how clean the drawings go in, which is exactly what an in-house plan set drawn by the people who answer the city's comments is for.
On a good share of the city, yes — this is a real San Jose issue, not boilerplate. The east-side and west-side hills carry expansive clay and old landslide ground; the low areas toward Alviso and the baylands sit in liquefaction and flood mapping with soft, settlement-prone soil; and even the valley flats in Willow Glen, Cambrian, and Berryessa carry enough clay that a standard slab can't simply be assumed. Each of those calls for a different foundation answer, from drilled piers on a slope to a raised or engineered footing near the bay. We pull a geotech report on the parcels where slope, clay, or liquefaction is in play, so the foundation in your contract is engineered to your dirt instead of an optimistic guess.
Long-term rentals of 30 days or more are the standard, no-friction ADU use across San Jose's residential zones, and that's what most of our clients here do — Silicon Valley demand keeps a one-bed occupied fast. Short-term rentals under 30 days are a separate, more regulated conversation: San José limits and registers short-term rentals, and the rules are stricter than for a normal lease. If a short-stay model is your plan, confirm the current city short-term-rental rules before you build. For steady, dependable income in this market, a long-term lease is the cleaner and stronger path.
Yes, deliberately and for the right projects. We're a Sacramento design-build outfit, CA license #1119373, and San Jose is about a two-hour, 130-mile run down I-680 or I-880. We don't pretend that's around the corner — it's a real drive, which is why we take the larger San Jose ADU jobs where homeowners want Sacramento-area craftsmanship and pricing discipline on a build that's worth the travel. A detached unit, a serious garage conversion, a hillside project: those justify the trip and get a steady crew presence, not a contractor who vanishes for two weeks. Call (916) 677-9774 and we'll talk through whether your project is the right fit.
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Save up to $5,000 on your detached, attached, or garage-conversion ADU. Permits and design included.
We treat every home like it's our own — quality work, clear communication, and happy homeowners.
PaulOwner · Future Generation
7 min read1,524 words8 sections
Building an ADU in San Jose: what a Sacramento contractor learned working Santa Clara County
San Jose is the biggest city in the Bay Area and the capital of Silicon Valley, and it does not build like the inland suburbs we call home. Lots are small and worth a fortune. Half the desirable neighborhoods climb hills with clay and landslide ground; the low valley sits in liquefaction and flood mapping. The permit counter runs big-city volume, rents are among the highest in the country, and a backyard unit here is a six-figure footprint on a tenth of an acre. We're a Sacramento design-build crew that takes the San Jose jobs worth the drive. Here's the honest version.
01Section
Why Silicon Valley made the San Jose backyard pay
San Jose didn't start as a tech city. It was the farm hub of the Santa Clara Valley, the old "Valley of Heart's Delight," before the chip business paved the prune trees and grew it into the third-largest city in California. That boom left a mostly mid-century housing stock: postwar ranches, tract homes, older bungalows in the pockets that predate it. What it did not leave is land. The valley filled in, the hills got built to the edge of buildable, and home prices went where they went.
That pressure is what makes an ADU pencil here even at Bay Area build costs. When a modest house clears seven figures and a one-bedroom rents for what a mortgage costs elsewhere, the unused 600 square feet behind your house becomes the most valuable thing you can build. Families double up across generations; tech workers pay a premium for a private detached unit. State ADU law forced the city to approve a compliant set ministerially instead of routing it to a hearing a neighbor could kill. Demand was never the question. The land and the rules were.
